diff mbox series

[07/21] dt-bindings: net: x-powers: add AC200 EPHY control

Message ID 20260802-submit-acx00-of-dynamic-v1-v1-7-0a53cd9e21cc@gmail.com (mailing list archive)
State New
Headers
Series net: phy: add X-Powers AC200/AC300 EPHY support |

Commit Message

James Hilliard Aug. 3, 2026, 5:14 a.m. UTC 
The AC200 companion IC contains a Fast Ethernet PHY controlled through
the parent AC200 I2C regmap.

Describe its control function, including the interface mode and optional
SoC SID calibration cell. The vendor sequence adds three to the calibration
value modulo 16 before writing the BPS_EFFUSE field. If the SID cell is
omitted, the driver can use the AC200's internal copy of the calibration
eFuse. The link-PHY driver supplies its Clause 22 address when enabling the
control function.

Signed-off-by: James Hilliard <james.hilliard1@gmail.com>
---
 .../bindings/net/x-powers,ac200-ephy-ctl.yaml      | 46 ++++++++++++++++++++++
 1 file changed, 46 insertions(+)

Comments

Andrew Lunn Aug. 3, 2026, 1:40 p.m. UTC | #1 
> +  phy-mode:
> +    enum:
> +      - mii
> +      - rmii

Despite the phy- bit, phy-mode is a MAC property, it defines the MII
the MAC uses. I would not expect to see this anywhere else.

The PHY driver is told what MII to use, phydev->interface, which takes
the values PHY_INTERFACE_MODE_RMII, PHY_INTERFACE_MODE_MII etc.

Please explain why you need this here, why is the MAC nodes phy-mode
property not sufficient.

    Andrew
James Hilliard Aug. 3, 2026, 6:03 p.m. UTC | #2 
On Mon, Aug 3, 2026 at 7:40 AM Andrew Lunn <andrew@lunn.ch> wrote:
>
> > +  phy-mode:
> > +    enum:
> > +      - mii
> > +      - rmii
>
> Despite the phy- bit, phy-mode is a MAC property, it defines the MII
> the MAC uses. I would not expect to see this anywhere else.
>
> The PHY driver is told what MII to use, phydev->interface, which takes
> the values PHY_INTERFACE_MODE_RMII, PHY_INTERFACE_MODE_MII etc.
>
> Please explain why you need this here, why is the MAC nodes phy-mode
> property not sufficient.

I have reworked this for v2. The phy-mode properties will be removed from
both control bindings and their DT nodes, leaving the MAC node as the sole
source of the interface mode. The PHY driver instead passes
phydev->interface to the selected control provider.

There is one ordering complication: the control block must be powered before
the Clause 22 PHY identification registers become accessible, which happens
before a MAC has attached. Early discovery therefore uses the hardware's
reset-default MII mode.

For v2, I split the provider interface into separate power_on() and
set_interface() operations. Once the MAC has supplied phydev->interface, the
PHY reset path calls set_interface(). If the provider is already powered,
this changes only the RMII_SEL bit; the normal phylib soft reset then
completes the handoff. It does not repeat the full control-block power and
reset sequence.

>
>     Andrew
diff mbox series

Patch

diff --git a/Documentation/devicetree/bindings/net/x-powers,ac200-ephy-ctl.yaml b/Documentation/devicetree/bindings/net/x-powers,ac200-ephy-ctl.yaml
new file mode 100644
index 000000000000..b3337c3aa62a
--- /dev/null
+++ b/Documentation/devicetree/bindings/net/x-powers,ac200-ephy-ctl.yaml
@@ -0,0 +1,46 @@ 
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/net/x-powers,ac200-ephy-ctl.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: X-Powers AC200 Ethernet PHY control
+
+maintainers:
+  - James Hilliard <james.hilliard1@gmail.com>
+
+description:
+  The AC200 Ethernet PHY control function configures and powers the Fast
+  Ethernet PHY in the AC200. Its registers are accessed through the parent
+  AC200 I2C regmap.
+
+properties:
+  compatible:
+    const: x-powers,ac200-ephy-ctl
+
+  nvmem-cells:
+    maxItems: 1
+    description:
+      Optional SoC SID cell containing the Ethernet PHY calibration value
+      written to the AC200 BPS_EFFUSE field after adding 3 modulo 16, as
+      prescribed by the vendor initialization sequence. If omitted, the
+      driver reads the AC200's internal copy of the calibration eFuse.
+
+  nvmem-cell-names:
+    const: calibration
+
+  phy-mode:
+    enum:
+      - mii
+      - rmii
+
+required:
+  - compatible
+  - phy-mode
+
+dependentRequired:
+  nvmem-cells: [ nvmem-cell-names ]
+  nvmem-cell-names: [ nvmem-cells ]
+
+additionalProperties: false
+...